Time-element device



Dec. 4, 1928. 1,694,240

L. S. WALLE TIME ELEMENT DEVICE Filed Feb. 1926 Fig.

AAAAAAAL LudK/Qg. 5 WaHe,' by Z41: Hs Abborney.

Patented Dec. 4, 1928.

UNITED STATES PATENT OFFICE.

LUDVIG S. WALLE, OF SCOTIA, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

TIME-ELEMENT DEVICE.

Application filed February My invention relates to improvements in timeelement devices, and more particularly to time element circuitcontrolling devices for the control 01'' electric circuits, especiallyon the occurrence of abnormal circuit conditions, and has for an objectto provide a time element device having improved operatingcharacteristics.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

In the accompanying drawing, Fig. 1 illustrates, partly in elevation andpartly in sec tion, a time element device embodying my invention; Fig. 2illustrates diagrammatically an embodiment of my invention in a timeelement circuit controlling device; and Fig. 3 is a detail of anadjusting device for the embodiment of my invention shown in Fig. 1.

The switching arrangement illustrated in Fig. 2 comprises a movablecircuit controlling member such as the contact operating rod of acircuit breaker 1 arranged to control a circuit 2. The operation of thecircuit controlling member is controlled by means comprising anelectroresponsive device 3 herein shown as arranged to control thecircuit breaker trip coil 4. The electroresponsive device 3 may be asubstantially instantaneous relay which in accordance with my inventionis arranged to be energized from the circuit 2 and to have itsenergization controlled by means such as a motor element 5, a physicalembodiment of which is shown in Fig. 1. The motor element, or moresimply, motor, is herein shown as of the series commutator type having afield Winding 6 and an armature 7 connected to be energized from thecircuit 2 as through a current transformer 8.

In order to obtain a time action dependent on a predetermined electriccondition, such as an abnormal circuit condition or fault causingcurrent in excess of a predetermined value, the Winding of the relay 3is connected in circuit with the motor 5 so that the energization of therelay depends on the counterelectromotive force of the motor and theimpedance of the armature. Since the counterelectromotive force isdependent on the speed or angular velocity of the armature 7, the motor5 is arranged normally to be inactive so that very little current flowsin the relay winding but to be set into operation when the 5, 1926.Serial No. 86,334.

predetermined electric condition occurs. WVith the relay windingconnected in parallel to the armature 7, as shown, the current flowingin' the relay winding when the armature is not rotating depends on therelative impedances of the relay and the armature, and as the speed ofthe armature increases, more and more current is diverted through therelay winding due to the increasing counterelectromotive force of thearmature until a current sufiicient to operate the relay occurs. Fornormally restraining the armature 7 against movement and yet undercertain conditions permitting its angular velocity to build up with atime delay action, the armature is yieldably supported and is arrangedto have a. substantial moment of inertia. As shown, the armature shaft 9may be slidably journaled in bearings 10, 11 and yieldably supported ona thrust bearing 12, herein illustrated as of the ball type andsupported by suitable resilient means such as a spring -13. The inertiamay be provided by a fly wheel 14L secured to the shaft 9 and having itsmass substantially concentrated in the rim. The weight of the flywheel14 is such as to hold the armature 7 down against the pressure oi? the.spring 12 with the flywheel engaging a braking surface such as a disc 15of suitable material for example leather so as to restrain the armatureagainst rotation.

= t'e cur 1 necessary to raise rctate, suitable on of the arma- .i, thismeans conisuch as a plug 17 supported on the v be secured against a:(if;

motor ihis plug a movement by a jatznb nut which also locks a. positionor adjustment indicator such as a notched member 19 against movemen Theposition of the flywheel 14c on the shaft 9 for any given adjustment canreadily b changed by means of the set-screw 20.

Assuming normal circuit conditions and the parts positioned as shown indrawing, there is not enough current in the winding oi the relay 3 tocause operation thereof,

since the armature 7 of the motor 5 is not Any condition on the circuit1 Ullv moving. causing a current sufiicient to raise the armature 7 andits associated parts so that rotation thereof can occur, causes thecounter electromotive force of the motor to build up as the speed of themotor is increased and i'elocity of the mature, and ele one meanscomprising :1 Wmdi in paral el with the arm ire and ar sible to oboperation over a u shown itis 3 d1scrnnineting in the time-currentchziracte over-c a- 1cm \zilues nhlcn enceen an thin; ill er-rceee oiscverl times normal loath since enough (l current the 788568 throueh thelOiZW Wind mg berore -hc armature builds up any counter QleCtIOlnOtl JQforce.

\Vhile l he e shown my inx motor 5 is so plicd from the c former 8, itis to he underi tor vention may he applied to dircc (nits in which casemotor 5 \\'i nected in ser'es rela with to an alternatiro currentcircuit n too where over-current protection is c will also he understoodthat cl ii e; and (:1- riations in the particular construction disclosed may he made without departing from my invention.

What I claim new and desire to secure by Letters Patent of the UnitedStates, is

l. A time element circuit controlling! device comprising a relay havinga Winding connected to be energized from the circuit and means forcontrolling the energization of the relay comprising motor having anarmature connected in circuit with the relay Winding, means to norn allyrestraining the armature against movement arranged to perinitmovement ofthe armature on t e occurrence of an a Ylinll circuit cond and i} w toretard the build up of the angular velOCl L'y of the armature whereby todelay the operation of the re" counter clectroinotii'e 2. A time elementcircuit vice comprising a motor havi connected to be energized in thecircuit curr nt, means straining the armature an I ranged to permitmovement 0 on tl occurrence of e predetern i ie A and to r to. d thebuilding up of I to be acmated after on the counter elec mature.

3. A time element done comprising a normally inactive motor arranged tohe set into operation when energized by current or predetermined valueand prorided with a rotatable armature arranged to have a substana t trotiol moment of inertia, and means compris ing a winding in circuit withth motor armature and arranged to he actuated when the counterelectroniotive force of the motor as- 2 ent do or U L all wi l L X (LLcomprising a na c1 cont ling *llfcl elcctro x, re 'neans i'or c' itr )ltand a normallv inartiie llldtul pron: iii-tn an aimati e arranged to onc a Elli tented moment or mcrust and to he =01; ed on the occcrrence oi:

ture lr concition, the airman 1 "ll-6i to choc; o1 controlling ember tin1 counter electromoti'z'c force of the artime limit circ 'io' a i l w i1 'q c the cm: ho encre' 'ori r .c ill? (3 I 1 MI till i clcctri'nnotiwill] oil cor .rc coil charactilt} tcrif icd loo by setting up acounter-electromotive force to oppose the current flowing through it,whereby to cause time delayed operation of said trip coil upon overload.

9. An overload protective device for an electric circuit including atrip coil, a source of energy for said trip coil responsive to thecurrent flowing in the circuit to be protected. and means adapted undernormal conditions to divert current from said trip coil, said meansincluding a device shunted across said trip coil and characterized byoperating under overload conditions in the circuit to build upacounter-clectromotive force and thereby cause increased current to flowthrough said trip coil.

In Witness whereof, I have hereunto set my hand this 4th day ofFebruary, 1926.

LUDVIG S. WALLE.

